Many borehole tools need to lock to hold their set position. This has been accomplished in the past with body lock rings that are typically a single piece with a split for ease of assembly and for retention of a net potential energy force, typically toward an internal mandrel that has one part of a mating ratchet profile. The lock ring has a mating part of the ratchet profile so that relative movement with respect to a mandrel of an outer assembly that has the lock ring will bring the ratchet pattern on the lock ring into contact with the ratchet pattern on the mandrel. Because of the shape of the opposed profiles that come into contact during setting movement, relative movement of an outer assembly around the mandrel and the mandrel itself is permitted until the tool sets. Relative movement in an opposite direction is prevented by the shape of the mating ratchet profiles.
The ratchet ring can be a 360 degree complete ring with axially extending spaced segments as described in US 20170167217. Other examples of traditional locking rings can be seen in U.S. Pat. Nos. 7,448,591; 6,209,653 and 7,222,889.
Using biased lock ring segments in close end spacing is illustrated in US 20160168945 in FIG. 8. The segments are spring biased from recesses in an exterior elongated lug that retains the segments axially in a recess in a surrounding housing. The biasing springs abut the recess and push the lug toward a mating pattern on an internal mandrel. This reference allows for the segments to be pushed out from within mandrel openings so as to release the set position of a tool for retrieval.
U.S. application Ser. No. 15/259,246 reveals the use of spaced lock ring segments with sufficient circumferential gaps to accept bars that transfer force past lock rings to a settable component below in a situation where another tool component has been set earlier without a substantial drift reduction of a passage through the tool.
What is needed and offered by the present invention is a retention feature on the outer surface of the locking segments that allows them to be radially biased into an opposed ratchet profile so that relative movement in a first direction is enabled by ratcheting as the segment jumps an opposing profile mounted to a mandrel, for example. The segments can be supported on a mandrel or on an opposing housing and still operate in the same manner. Relative movement in the opposite direction is prevented by each segment as each such segment is retained against axial movement by an outer profile that can be a spiral pattern, undulating parallel ridges or other patterns that are either discrete or continuous as will be explained below. A bias can be applied at one or both axial ends of each segment or in between ends. The biasing can be realized by coiled or wave springs located between the outer face of the segments and the mating retention profile in a surrounding outer housing. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims.